The invention pertains to a process for recovery of nickel and magnesium from a naturally occurring material.
Various hydrometalurgical processes for extracting nickel from nickel bearing metals are known in the art. For example, U.S. Pat. No. 4,435,369 to Simpson discloses a process whereby nickel bearing metals are contacted in an extraction zone with an aqueous solution having a concentration of chloride ions, metal ions and sulfuric acid at an elevated temperature. This procedure yields a nickel recovery of approximately 70%. Unfortunately, the materials necessary for this procedure, namely the sulfuric acid and metal and chloride ions, are costly and thus limit the application of this procedure to use on nickel bearing metals having a sufficiently high portion of nickel to make the procedure economically feasible. Further, the procedure disclosed in U.S. Pat. No. 4,435,369 requires the addition of magnesium in the extraction zone to improve the results of the procedure.
Several other methods of hydrometalurgical processes, discussed in U.S. Pat. No. 4,435,369, similarly have poor recovery percentages which limit the use of such processes to applications where the nickel content of the nickel bearing ore must be sufficiently high to make the procedure economically feasible.
Magnesium is an additional metal which would preferably be extracted during the process, rather than being required as an additive to the process in order to improve the recovery of nickel.
Accordingly, it is a principal object of the present invention to provide a process for recovery of both nickel and magnesium from naturally occurring materials whereby the cost of the procedure is reduced to allow application of the process to nickel and magnesium bearing metals having a much lower content of these metals. Due to the reduced cost of the extraction materials of the disclosed invention, as well as the improved efficiency of the process, metals having a low content of nickel and magnesium can be treated in a commercially feasible manner to extract these metals.
Hydroconversion treatments of heavy hydrocarbon oils frequently result in production of spent catalysts which have high sulfur content and which are also iron based. Typical iron based catalysts used in these processes are disclosed in U.S. Pat. Nos. 3,936,371 to Ueda et al., U.S. Pat. No. 4,066,530 to Aldridge et al., and U.S. Pat. No. 4,591,426 to Krasuk et al. It would therefore also be desirable to provide a use for such spent hydroconversion iron based catalysts which does not involve costly procedures for its safe disposal.
It is therefore a further object of the present invention to provide a use for these spent hydroconversion catalysts in the presently disclosed process for recovery of nickel and magnesium.